Enable creating CouchDB attachments for images

streampipes-model/src/main/java/org/apache/streampipes/model/file/GenericStorageAttachment.java

@@ -0,0 +1,44 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+package org.apache.streampipes.model.file;
+
+public class GenericStorageAttachment {
+  String contentType;
+  byte[] attachment;
+
+  public GenericStorageAttachment(String contentType, byte[] attachment) {
+    this.contentType = contentType;
+    this.attachment = attachment;
+  }
+
+  public String getContentType() {
+    return contentType;
+  }
+
+  public void setContentType(String contentType) {
+    this.contentType = contentType;
+  }
+
+  public byte[] getAttachment() {
+    return attachment;
+  }
+
+  public void setAttachment(byte[] attachment) {
+    this.attachment = attachment;
+  }
+}

streampipes-storage-api/src/main/java/org/apache/streampipes/storage/api/IGenericStorage.java

@@ -18,6 +18,8 @@
 
 package org.apache.streampipes.storage.api;
 
+import org.apache.streampipes.model.file.GenericStorageAttachment;
+
 import java.io.IOException;
 import java.util.List;
 import java.util.Map;
@@ -35,4 +37,9 @@ public interface IGenericStorage {
   Map<String, Object> update(String id, String payload) throws IOException;
 
   void delete(String id, String rev) throws IOException;
+
+  void createAttachment(String docId, String attachmentName, String contentType, byte[] payload, String rev)
+      throws IOException;
+
+  GenericStorageAttachment findAttachment(String docId, String attachmentName) throws IOException;
 }

streampipes-storage-couchdb/src/main/java/org/apache/streampipes/storage/couchdb/impl/GenericStorageImpl.java

@@ -18,6 +18,7 @@
 
 package org.apache.streampipes.storage.couchdb.impl;
 
+import org.apache.streampipes.model.file.GenericStorageAttachment;
 import org.apache.streampipes.storage.api.IGenericStorage;
 import org.apache.streampipes.storage.couchdb.constants.GenericCouchDbConstants;
 import org.apache.streampipes.storage.couchdb.utils.Utils;
@@ -103,6 +104,25 @@ public void delete(String id, String rev) throws IOException {
     Content content = executeAndReturnContent(req);
   }
 
+  @Override
+  public void createAttachment(String docId,
+                               String attachmentName,
+                               String contentType,
+                               byte[] payload,
+                               String rev) throws IOException {
+    Request req = Utils.putRequest(
+            getDatabaseRoute() + SLASH + docId + SLASH + attachmentName + "?rev=" + rev, payload, contentType
+    );
+    executeAndReturnContent(req);
+  }
+
+  @Override
+  public GenericStorageAttachment findAttachment(String docId, String attachmentName) throws IOException {
+    Request req = Utils.getRequest(getDatabaseRoute() + SLASH + docId + SLASH + attachmentName);
+    Content content =  executeAndReturnContent(req);
+    return new GenericStorageAttachment(content.getType().getMimeType(), content.asBytes());
+  }
+
   private Map<String, Object> queryDocuments(String route) throws IOException {
     Request req = Utils.getRequest(route);
     Content content = executeAndReturnContent(req);

streampipes-storage-couchdb/src/main/java/org/apache/streampipes/storage/couchdb/utils/Utils.java

@@ -216,6 +216,12 @@ public static Request putRequest(String route,
     return append(Request.Put(route).bodyString(payload, ContentType.APPLICATION_JSON));
   }
 
+  public static Request putRequest(String route,
+                                   byte[] payload,
+                                   String contentType) {
+    return append(Request.Put(route).bodyByteArray(payload, ContentType.getByMimeType(contentType)));
+  }
+
   private static Environment getEnvironment() {
     return Environments.getEnvironment();
   }